Recommendations for a guy/girl duet?

Title really explains it, but I am looking for some songs that a guy/girl duo can sing in a talent show. It can be a song actually meant to be a duet, or it can be a song meant for one person, but does well as a duet (like Fifteen with Taylor Swift at the Gram mys). Both have vocal and acting training. The girl is a soprano and can sing up to a high G. The boy is a b, but can sing some tenor notes. A country or "soft music" song is preferred. A musical theatre song would be fine to.